U.S. patent application number 10/504683 was filed with the patent office on 2005-06-30 for primary carpet backing.
This patent application is currently assigned to Colbond B.V.. Invention is credited to Bouwmans, Leonardus Gerardus Cornelis, Lucas, Leonardus, Oosterbroek, Marten, Szoltek, Michal, Veurink, Jannes, Zuuring, Pieter Hendrik.
Application Number | 20050142325 10/504683 |
Document ID | / |
Family ID | 27675624 |
Filed Date | 2005-06-30 |
United States Patent
Application |
20050142325 |
Kind Code |
A1 |
Veurink, Jannes ; et
al. |
June 30, 2005 |
Primary carpet backing
Abstract
A nonwoven fabric is provided for a primary carpet backing
comprising a bicomponent filament of polymeric core/sheath-type,
the polymeric core component of which has a higher melting point
than the polymeric sheath component, said bicomponent filaments are
bonded together by the application of heat to form said fabric,
characterized in that the polymeric sheath component is selected
from the group containing polypropylene and copolymers comprising
polypropylene and/or blends thereof. The invention is further
directed to a process of manufacturing such nonwoven fabrics and to
articles, such as car carpets, comprising them.
Inventors: |
Veurink, Jannes; (Brummen,
NL) ; Lucas, Leonardus; (Duiven, NL) ;
Zuuring, Pieter Hendrik; (Nijmegen, NL) ; Szoltek,
Michal; (Giesbeck, NL) ; Oosterbroek, Marten;
(Westervoort, NL) ; Bouwmans, Leonardus Gerardus
Cornelis; (Didamn, NL) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
Colbond B.V.
Westervoortsedijk 73
Arnhem
NL
6800 TC
|
Family ID: |
27675624 |
Appl. No.: |
10/504683 |
Filed: |
October 15, 2004 |
PCT Filed: |
February 11, 2003 |
PCT NO: |
PCT/EP03/01302 |
Current U.S.
Class: |
428/95 ; 442/364;
442/409 |
Current CPC
Class: |
Y10T 428/23979 20150401;
D04H 3/007 20130101; D04H 3/147 20130101; D06N 2201/0254 20130101;
B60N 3/048 20130101; D06N 2201/10 20130101; D06N 7/0068 20130101;
D06N 2201/0263 20130101; D04H 3/14 20130101; Y10T 442/641 20150401;
Y10T 442/69 20150401; D04H 3/009 20130101; D01F 8/06 20130101; D06N
2201/02 20130101; D04H 3/011 20130101; D04H 11/00 20130101 |
Class at
Publication: |
428/095 ;
442/364; 442/409 |
International
Class: |
B32B 003/02; B32B
033/00; D04H 001/00; D04H 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2002 |
EP |
02003505.1 |
Claims
1. A nonwoven fabric for a primary carpet backing comprising
bicomponent filaments of a polymeric core component and a polymeric
sheath component, the polymeric core component of which has a
higher melting point than the polymeric sheath component, wherein
said bicomponent filaments are bonded together by the application
of heat to form said fabric, and wherein the polymeric sheath
component is selected from the group consisting of polypropylene,
copolymers comprising polypropylene and blends thereof.
2. The nonwoven fabric according to claim 1, wherein the melting
point of the polymeric core component is more than 30.degree. C.
higher than the melting point of the polymeric sheath
component.
3. The nonwoven fabric according to claim 1, wherein the polymeric
core component is selected from the group consisting of
polyethylene terephthalate, polybutylene terephthalate,
polyparaphenylene terephthalamide, aliphatic polyamides,
polyphenylene oxide co-polymers thereof and blends thereof.
4. The nonwoven fabric according to claim 1, wherein the ratio of
the polymeric core component to the polymeric sheath component is
in the range from 60:40 to 95:5 v/v %.
5. A carpet comprising a primary carpet backing, wherein the
primary carpet backing comprises the nonwoven fabric according to
claim 1.
6. A car carpet comprising a primary carpet backing, wherein the
primary carpet backing comprises the nonwoven fabric according to
claim 1.
7. A process for manufacturing the nonwoven fabric for the primary
carpet backing according to claim 1 comprising the steps of
providing the bicomponent filaments having the polymeric core
component and the polymeric sheath component, the polymeric core
component of which has a higher-melting point than the polymeric
sheath component, bonding said bicomponent filaments together by
application of heat to form said nonwoven fabric, wherein the
polymeric sheath component is selected from the group consisting of
polypropylene, copolymers comprising polypropylene and blends
thereof.
8. The nonwoven fabric according to claim 1, wherein the melting
point of the polymeric core component is more than 50.degree. C.
higher than the melting point of the polymeric sheath
component.
9. The nonwoven fabric according to claim 1, wherein the polymeric
sheath component is polypropylene.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The invention relates to a nonwoven fabric for a primary
carpet backing comprising a bicomponent filament of polymeric
core/sheath-type, the polymeric core component of which has a
higher melting point than the polymeric sheath component, said
bicomponent filaments are bonded together by the application of
heat to form said fabric.
[0003] 2. Description of Related Art
[0004] A spun bonded fabric consisting of polyester matrix
filaments that is suitable for use as a tufting base for carpets is
known from U.S. Pat. No. 4,842,915. The bonded-fabric base consists
of polyester matrix filaments and is bonded with polyolefins as the
binding component. The binding components are in the form of
thermoplastically softenable filaments consisting of advantageously
polypropylene.
[0005] Primary carpet backings comprising spun bonded fabrics
including binding fibers often show dissimilarities in their
appearance. Moreover, the overall strength of the fabrics in many
cases leaves room for improvement.
[0006] Furthermore, nonwoven fabrics comprising bicomponent
filaments having a polyethylene terephthalate core and a polyamide
sheath, in the following also referred to as PET/PA bicomponent
filaments, suitable for primary carpet backings are known. The
nonwoven fabrics based on PET/PA bicomponent filaments are easily
moldable and show good homogeneity and also considerable strength
when used in primary carpet backings.
[0007] Unfortunately, molded carpets containing a primary backing
based on PET/PA exhibit a relatively high shrinkage. Molded carpets
are known to the person skilled in the art and need not to be
elucidated here. Also a relatively high molding temperature is
necessary when manufacturing car carpets having primary carpet
backings on PET/PA basis.
SUMMARY OF THE INVENTION
[0008] The present invention seeks to at least reduce the problems
mentioned above. Furthermore, it has for its object to provide a
nonwoven fabric useful as a primary carpet backing, which is easily
and inexpensively manufactured, shows a good long term stability
and easy molding behavior.
[0009] Surprisingly, the object of the invention can be achieved by
a nonwoven fabric as described in the opening paragraph, wherein
the polymeric sheath component is selected from the group
containing polypropylene and copolymers comprising polypropylene
and/or blends thereof. Especially preferred is
homo-polypropylene.
[0010] In comparison to the nonwoven fabrics useful for primary
carpet backings of the prior art, the nonwoven fabric according to
the invention exhibits an improved homogeneity due to the fact that
there are no binding fibers necessary and at the same time has an
abundance of bonding points, which renders the fabric strong and
resistant against mechanical demands. The nonwoven fabric of the
present invention thus entirely consists of bicomponent filaments.
As a consequence every contact between filaments during the bonding
step returns in a bond point. In contrast to that, the nonwoven
fabrics of U.S. Pat. No. 4,842,915 always contain to a certain
extent filaments consisting of only one polymer type, i.e., the
polyester matrix.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] A car carpet comprising a nonwoven fabric of the invention
can be molded more easily and will show lower shrinkage after
molding. In fact, the polypropylene forms a continuous phase
covering the core polymer everywhere in the nonwoven fabric. As a
consequence of the high chemical inertness of the polypropylene,
the nonwoven fabric also shows good resistance against chemicals.
Many carpets have to be dyed after tufting; the hydrophobic nature
of the continuous phase diminishes the pick up of the dyestuff,
which is an economical advantage.
[0012] It is of further advantage for the nonwoven fabric of the
invention when the melting point of the polymeric core component is
more than 30.degree. C., preferably more than 50.degree. C., higher
than the melting point of the sheath component. A relatively large
difference between the melting temperature of the polymeric core
component and the binding or molding temperature while forming the
nonwoven fabric prevents the degradation of the mechanical
properties of the polymeric core component during processing. In
addition to the low degradation of the polymeric core component
while binding, there is also less structural change of the core
component, which ensures that the overall properties of the
bicomponent filaments are better retained.
[0013] When applying polypropylene as the polymeric sheath
component, the bonding temperature is substantially lower than in
case of e.g., polyamide 6, which requires a higher temperature.
[0014] For the polymeric core component, it is preferred that it is
selected from a group containing polyethylene terephthalate,
polybutylene terephthalate, polyparaphenylene terephthalamide,
aliphatic polyamides, polyphenylene oxide and/or co-polymers or
blends thereof. Polyethylene terephthalate as polymeric core
component is most preferred.
[0015] It is sufficient when the ratio of the polymeric core
component to the polymeric sheath component is in the range from
60:40 to 95:5% vol./vol. A typical example reads 73 vol.-% of
polyethylene terephthalate as polymeric core component and 27
vol.-% of polypropylene.
[0016] The polymeric core/sheath type bicomponent filaments of the
nonwoven fabric according to the invention ensure large contact
surfaces and form bonding points of good strength and
distribution.
[0017] The linear density of the bicomponent filaments is usually
in the range between 1 and 25 dtex, preferably between 2 and 15
dtex.
[0018] When used in primary carpet backing, the nonwoven fabric of
the invention combines long-term stability and easy molding. Also
in terms of tufting, it shows a good performance, i.e., good
mechanical anchoring realized with a single nonwoven without
additional modifications, which renders further layers in the
primary backing redundant.
[0019] As already indicated above, the present invention is also
directed to a carpet comprising a primary carpet backing, wherein
the primary carpet backing comprises a nonwoven fabric according to
the invention.
[0020] It is noted that JP 2-139465 discloses a nonwoven fabric for
a secondary carpet backing, the nonwoven fabric is made up of a
core-sheath-type composite fiber with polyethylene terephthalate as
the core component and polypropylene as the sheath component. This
publication, however, neither discloses nor teaches that the
nonwoven can be used for primary carpet backings.
[0021] A particularly preferred embodiment is a car carpet
comprising a primary carpet backing, wherein the primary carpet
backing comprises a nonwoven fabric according to the invention.
[0022] The present invention is also directed to a process for
manufacturing a nonwoven fabric for use as a primary carpet backing
comprising the steps of providing a bicomponent filament of
polymeric core/sheath-type, the polymeric core component of which
has a higher melting point than the polymeric sheath component,
bonding said bicomponent filaments together by the application of
heat to form said fabric, wherein the polymeric sheath component is
selected from the group containing polypropylene and copolymers
comprising polypropylene and/or blends thereof.
[0023] The invention will now be further elucidated by the
following non-limiting example.
EXAMPLE
[0024] Bicomponent PET/PP yarn is produced using a known melt
spinning technique and a core/sheath spinneret, such that each
filament has a core/sheath geometry, where the core is made from
polyethyl terephthalate(PET) having a relative viscosity of 1.65
and the sheath of polypropylene with a melt flow rate (MFR) of 23
g/10 min at 230.degree. C./2.16 kg according to ISO 1133. The
relative viscosity of PET reflects the viscosity that would be
obtained using 1 g/100 g PET in m-cresol. The core/sheath ratio
amounts to 73.7/26.3 (v/v).
[0025] The filament bundle was cooled in a blow-box and a
subsequent chute. In the take up section, the yarn was stretched
2.1 times and wound up at a speed of 2320 m/min. Total yarn count
was 1200 dtex.
[0026] Nonwovens have been made from these yarns using a web-laying
machine followed by thermal bonding at 165.degree. C.
[0027] The resulting nonwoven weighs 120 g/m.sup.2. The strength in
machine and cross machine direction is 360 and 330 N/5 cm. The
strain at break amounts to 80%. The nonwoven is suitable as primary
backing in car carpets. A molded carpet with good dimensional
stability has been obtained after the necessary process steps, as
tufting, dyeing, coating, application of a heavy layer and a
secondary backing, and molding. The shrinkage of the deep drawn
molded carpet is less than 2% in machine direction and 0% in cross
machine direction after treatment at 160.degree. C. during 15
minutes.
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